setup.c

   1 #include "cache.h"
   2
   3 const char *prefix_path(const char *prefix, int len, const char *path)
   4 {
   5         const char *orig = path;
   6         for (;;) {
   7                 char c;
   8                 if (*path != '.')
   9                         break;
  10                 c = path[1];
  11                 /* "." */
  12                 if (!c) {
  13                         path++;
  14                         break;
  15                 }
  16                 /* "./" */
  17                 if (c == '/') {
  18                         path += 2;
  19                         continue;
  20                 }
  21                 if (c != '.')
  22                         break;
  23                 c = path[2];
  24                 if (!c)
  25                         path += 2;
  26                 else if (c == '/')
  27                         path += 3;
  28                 else
  29                         break;
  30                 /* ".." and "../" */
  31                 /* Remove last component of the prefix */
  32                 do {
  33                         if (!len)
  34                                 die("'%s' is outside repository", orig);
  35                         len--;
  36                 } while (len && prefix[len-1] != '/');
  37                 continue;
  38         }
  39         if (len) {
  40                 int speclen = strlen(path);
  41                 char *n = xmalloc(speclen + len + 1);
  42
  43                 memcpy(n, prefix, len);
  44                 memcpy(n + len, path, speclen+1);
  45                 path = n;
  46         }
  47         return path;
  48 }
  49
  50 /*
  51  * Unlike prefix_path, this should be used if the named file does
  52  * not have to interact with index entry; i.e. name of a random file
  53  * on the filesystem.
  54  */
  55 const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
  56 {
  57         static char path[PATH_MAX];
  58         if (!pfx || !*pfx || arg[0] == '/')
  59                 return arg;
  60         memcpy(path, pfx, pfx_len);
  61         strcpy(path + pfx_len, arg);
  62         return path;
  63 }
  64
  65 /*
  66  * Verify a filename that we got as an argument for a pathspec
  67  * entry. Note that a filename that begins with "-" never verifies
  68  * as true, because even if such a filename were to exist, we want
  69  * it to be preceded by the "--" marker (or we want the user to
  70  * use a format like "./-filename")
  71  */
  72 void verify_filename(const char *prefix, const char *arg)
  73 {
  74         const char *name;
  75         struct stat st;
  76
  77         if (*arg == '-')
  78                 die("bad flag '%s' used after filename", arg);
  79         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
  80         if (!lstat(name, &st))
  81                 return;
  82         if (errno == ENOENT)
  83                 die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
  84                     "Use '--' to separate paths from revisions", arg);
  85         die("'%s': %s", arg, strerror(errno));
  86 }
  87
  88 /*
  89  * Opposite of the above: the command line did not have -- marker
  90  * and we parsed the arg as a refname.  It should not be interpretable
  91  * as a filename.
  92  */
  93 void verify_non_filename(const char *prefix, const char *arg)
  94 {
  95         const char *name;
  96         struct stat st;
  97
  98         if (*arg == '-')
  99                 return; /* flag */
 100         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
 101         if (!lstat(name, &st))
 102                 die("ambiguous argument '%s': both revision and filename\n"
 103                     "Use '--' to separate filenames from revisions", arg);
 104         if (errno != ENOENT)
 105                 die("'%s': %s", arg, strerror(errno));
 106 }
 107
 108 const char **get_pathspec(const char *prefix, const char **pathspec)
 109 {
 110         const char *entry = *pathspec;
 111         const char **p;
 112         int prefixlen;
 113
 114         if (!prefix && !entry)
 115                 return NULL;
 116
 117         if (!entry) {
 118                 static const char *spec[2];
 119                 spec[0] = prefix;
 120                 spec[1] = NULL;
 121                 return spec;
 122         }
 123
 124         /* Otherwise we have to re-write the entries.. */
 125         p = pathspec;
 126         prefixlen = prefix ? strlen(prefix) : 0;
 127         do {
 128                 *p = prefix_path(prefix, prefixlen, entry);
 129         } while ((entry = *++p) != NULL);
 130         return (const char **) pathspec;
 131 }
 132
 133 /*
 134  * Test if it looks like we're at the top level git directory.
 135  * We want to see:
 136  *
 137  *  - either a .git/objects/ directory _or_ the proper
 138  *    GIT_OBJECT_DIRECTORY environment variable
 139  *  - a refs/ directory under ".git"
 140  *  - either a HEAD symlink or a HEAD file that is formatted as
 141  *    a proper "ref:".
 142  */
 143 static int is_toplevel_directory(void)
 144 {
 145         if (access(".git/refs/", X_OK) ||
 146             access(getenv(DB_ENVIRONMENT) ?
 147                    getenv(DB_ENVIRONMENT) : ".git/objects/", X_OK) ||
 148             validate_symref(".git/HEAD"))
 149                 return 0;
 150         return 1;
 151 }
 152
 153 const char *setup_git_directory_gently(int *nongit_ok)
 154 {
 155         static char cwd[PATH_MAX+1];
 156         int len, offset;
 157
 158         /*
 159          * If GIT_DIR is set explicitly, we're not going
 160          * to do any discovery, but we still do repository
 161          * validation.
 162          */
 163         if (getenv(GIT_DIR_ENVIRONMENT)) {
 164                 char path[PATH_MAX];
 165                 int len = strlen(getenv(GIT_DIR_ENVIRONMENT));
 166                 if (sizeof(path) - 40 < len)
 167                         die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 168                 memcpy(path, getenv(GIT_DIR_ENVIRONMENT), len);
 169
 170                 strcpy(path + len, "/refs");
 171                 if (access(path, X_OK))
 172                         goto bad_dir_environ;
 173                 strcpy(path + len, "/HEAD");
 174                 if (validate_symref(path))
 175                         goto bad_dir_environ;
 176                 if (getenv(DB_ENVIRONMENT)) {
 177                         if (access(getenv(DB_ENVIRONMENT), X_OK))
 178                                 goto bad_dir_environ;
 179                 }
 180                 else {
 181                         strcpy(path + len, "/objects");
 182                         if (access(path, X_OK))
 183                                 goto bad_dir_environ;
 184                 }
 185                 return NULL;
 186         bad_dir_environ:
 187                 if (nongit_ok) {
 188                         *nongit_ok = 1;
 189                         return NULL;
 190                 }
 191                 path[len] = 0;
 192                 die("Not a git repository: '%s'", path);
 193         }
 194
 195         if (!getcwd(cwd, sizeof(cwd)) || cwd[0] != '/')
 196                 die("Unable to read current working directory");
 197
 198         offset = len = strlen(cwd);
 199         for (;;) {
 200                 if (is_toplevel_directory())
 201                         break;
 202                 chdir("..");
 203                 do {
 204                         if (!offset) {
 205                                 if (nongit_ok) {
 206                                         if (chdir(cwd))
 207                                                 die("Cannot come back to cwd");
 208                                         *nongit_ok = 1;
 209                                         return NULL;
 210                                 }
 211                                 die("Not a git repository");
 212                         }
 213                 } while (cwd[--offset] != '/');
 214         }
 215
 216         if (offset == len)
 217                 return NULL;
 218
 219         /* Make "offset" point to past the '/', and add a '/' at the end */
 220         offset++;
 221         cwd[len++] = '/';
 222         cwd[len] = 0;
 223         return cwd + offset;
 224 }
 225
 226 int git_config_perm(const char *var, const char *value)
 227 {
 228         if (value) {
 229                 if (!strcmp(value, "umask"))
 230                         return PERM_UMASK;
 231                 if (!strcmp(value, "group"))
 232                         return PERM_GROUP;
 233                 if (!strcmp(value, "all") ||
 234                     !strcmp(value, "world") ||
 235                     !strcmp(value, "everybody"))
 236                         return PERM_EVERYBODY;
 237         }
 238         return git_config_bool(var, value);
 239 }
 240
 241 int check_repository_format_version(const char *var, const char *value)
 242 {
 243        if (strcmp(var, "core.repositoryformatversion") == 0)
 244                repository_format_version = git_config_int(var, value);
 245         else if (strcmp(var, "core.sharedrepository") == 0)
 246                 shared_repository = git_config_perm(var, value);
 247        return 0;
 248 }
 249
 250 int check_repository_format(void)
 251 {
 252         git_config(check_repository_format_version);
 253         if (GIT_REPO_VERSION < repository_format_version)
 254                 die ("Expected git repo version <= %d, found %d",
 255                      GIT_REPO_VERSION, repository_format_version);
 256         return 0;
 257 }
 258
 259 const char *setup_git_directory(void)
 260 {
 261         const char *retval = setup_git_directory_gently(NULL);
 262         check_repository_format();
 263         return retval;
 264 }